Zigzag-stitch sewing machine



March 15, 1932. w. MYERS 1,849,332

ZIGZAG STITCH SEWING MACHINE Filed Jan. 10, 1930 2 Sheets-Sheet l Walter@0119 March 15, 1932. w. MYERS 1,849,332-

ZIGZAG STITCH SEWING MACHINE Filed Jan. 10, 1930 2 Sheets-Sheet 2 IJwomtw Waher ){yers yn r the loo ntaker correspond in direction andPatented Mar. 15, 1932 UNITED STATES FACTURING COMPANY, 033 ELIZABETH,NE\V JERSEY WALTER MYERS, OF BRIDGEPORT, CONNECTICUT, .ASSIGNORTOTHE'SINGER 'I VIANU- JERSEY, A CORPORATION OF NEW wZIGZAG-STITCH SEWINGMACHINE Application filed January 10, 1930. Serial No. 419,815.

This invention relates to improvements in zigzag-stitchsewing machinesand has for its primary object to provide improved actuating mechanismfor vibrating the reciprocatory-needle laterally and for maintainingloop-seizing relationship between the laterally-vibrating needle and aloop-taker which cooperates therewithv in'the formation of stitches. y

A further object of the invention is to provide a loop-takercompensating mechanism which is particularly adapted for a sewingmachine having a work-cylinder of small diameter, whereby tubulararticles of small compass may be readily stitched. j

Other and more specific objects of the invention will be apparent fromthe following description and claims. A preferred embodiment of theinvention has been designed more particularly for j oining straw-braidsby zigzag stitehes,although it is obviously adapted to other uses. Inthe present instance. the machine frame includes a work-supporting hornor cylinder and a bracket-arm overhanging the work-cylinder.

The endwise reciprocatoryneedle-bar is journaled in a vibratory-frame inthe bracketarm head. which frame is connected by a link with a pitmanhaving a strap embracing an actuating eccentric adjustably secured upona shaft rotating at one half the speed of the needle-reciprocatingshaft. j

The needle-vibrating pitman has a reciprocating pivotal-support which,in the preferred embodiment of the invention, is afforded by apivotal-connectionbetween an extension-arm of said pitman anda'rock-lever supported. by the bracket-arm. This rock'- lever has anadjustable connection with a second rock-lever imparting 'reeiprocatorymovements.longitudinally of the work-cylinder, to a bracket in which isjournaled a loop-taker of the vertical-axis rotary-hook The resultingshifting movements of extent with the lateral movements of the bracketisan arm having a needle-throat movable in a suitably aperturedthroat-plate or Fig. 1;

fixed upon the work-cylinder, said arm being provided with means forrestraining the lower-thread bobbin-case against rotation with theloop-taker in which said bobbin-case is journaled. j The loop-taker isrotated by gear-connections witha rotary, loop-taker actuating- .shaft,the drivinggear being splined upon said shaft and shifted longitudinallythereof tomaintain driving relationship between the gears during thelateral movements ofthe loop-taker.

-In the accompanying drawings, Fig. 1 is a longitudinal section, partlyin front elevation, of a sewing machine containing a pre ferredembodiment of the present improvement; Fig. 2 is a bottom-plan view ofthe base and work-cylinder of the machine, a portion of the free end ofthe cylinder being'in section. Fig. 3v isa sectional view of thework-cylinder substantially on the line 33 Fig. 4. is, a. sectional viewof the bracket-arm of the machine, substantially on theline 4+4 ofFig. 1. Fig. 5 is a perspective, View of the loop-taker and feedingmechanism, with the feed-bar-and its controlling link in detachedrelationship. Fig. 6' comprises perspective views of the throat-plateand of the needle-throat arm. Q

" Referring to the drawings, the present improvementis shown as embodiedin a sewing machine having abase 1, from which projects laterally awork-cylinder 2. Rising from the work-cylinder is the hollow'standard 3of a tubular bracket-arm 4, overhanging the worlecylinderand terminatingin ahead 5.

Jonrnaled in suitable hearings in the bracket-arm is a mainactuating-shaft 6, having the usual crank-disk 7 connected by means of alink 8 with aneedle-bar 9 to impart endwise reeiprocations thereto. Theneedle-bar 9, which at its lower end carries a needle 10, 'ieciprocatesin suitable bearings provided in a vibratory frame 11 supported atitsupper end by a pivot-pin12 in the bracketarm' head 5. r

Adjacent its free end, the frame 11 is pivotally connected by a stud 13with one end of a link 14,.of which the opposite end is connected by ataper-headed screw-bolt 15 with one arm 16 of a two-armed pitman 16, 17.Intermediate its ends, said pitman has a split hub or strap 18 embracingan actuatingecc-entric 19, which extends laterally froman'eccentric-frame 20. The eccentric-frame 20 is pivotally supported bya screw-bolt 21 upon a disk 22 having a hub 23 secured by a screw 24upon a cross-shaft 25. This crossshaft 25 is journaled in suitablebearings provided in the bracket-arm 4 so as to be disposed under andtransversely of the mainshaft 6, said cross-shaft 25 carrying awormwheel 26 driven by a main-shaft worm-gear 27 at one half the speedof said main-shaft. In order to adjust the actuating-eccentric 19withrespect to the cross-shaft 25 and thereby change the degree of theeffective or endwise movement of the pitman 16, 17, there is provided anadjusting rod 28 threaded into a longitudinal bore of the cross-shaft 25and having a knurled-head 29. The tapered end 30' of the rod 28 engagesthe rounded end of ascrew 31 adjustably threaded into theeccentric-frame 20 and entering a suitable aperture in the cross-shaft25. Opposed to the screw 31 is a plunger 32 bearing against the shaftunder the action of a spring 33 disposed in a socket in the frame 20.The pressure of the spring 33' may be regulated by means of a screw 34.The described eccentric-supporting and -adjusting means is constructedsubstantially in accordance with the disclosure in the patent to C. F.Gray, No. 1,020,089,. Mar.

'The arm 17 of the two-armed pitman is connected by a taper-headedpivot-bolt 35 with an arm 36 of a rock-lever 36, 37 having intermediateits ends a hub 38 fulcrumed between two collars 39 upon a horizontallydisposed bar 40 mounted in apertures in the front and rear walls of thebracket-arm, said bar 40 being substantially parallel with thecross-shaft 25. The free end of the arm 37 of said rock-lever 36, 37,has a threaded aperture adjustably receiving a: ball-headed screw 41,fixed therein by a check-nut 42. A ball 43 at one end of the screw 41 isslidably fitted into an elongated ball-aperture 44 provided in the splitupper end of an arm 45 of a second rock-lever 45, 46. A clamp-screw 47is preferably employed for adjusting the size of the ball-aperture 44.It is evident that the described connection provides for slightlychanging the throw of the arm 45 with respect to that of the lever-arm37.

The rocklever 45, 46 is fulcrumed upon a bar 48 supported by thebracket-arm standard 3 similarly to and substantially parallel with thebar 40. Upon the flattened lower end a; of the arm46 is suitably securedone end of a flat-spring 49 of which the other end is suitably fixedupon an endwise-reciprocatory bar 50, said spring 49 constituting ayielding connection between the arcuately movable leverarm 46 and theright-line reciprocating bar 50. The bar 50 is j ournaled in alinedbearingapertures provided within the work-cylinder ing inwardly from thework-cylinder wall,

whereby said bracket is restrained against angular movement about theaxis of the bar Journaled in a suitable bearing provided in thebracket53 is a vertically disposed shaft 56 carrying at its upper end aloop-taker 57. The loop-taker 57 is of the rotary-hook type having aloop-seizing beak 58 adapted to seize thread-loops presented by theneedle and cast sai lloops about a mass ofunder-thread contained withina bobbin-case 59, journaled as usual in the loop-taker. It will beobserved th the loop-taker is located at the side of the needle pathopposite to that occupied by the free end of the work-cylinder andconsequently the work-cylinder may terminate abruptly closely adj acentto said needle-path, a feature which is highly desirable for certainclasses of work. Access to theloop-taker and the lower-thread bobbin isafforded by the usual slide-plate 60 upon the top of the work-cylinder.At its-lower end, the loop-taker shaft 56 carries a bevel-gear 61 inmesh with a similar gear 62 of twice the size'of the gear 61, thedriving-gear 62 being slidably secured by a spline 63 upon a loop-takeractuating shaft 64. The shaft 64 is journaled in bearings within thework-cylinder andcarries'a pulley 65 connected by a cleated-belt 66 witha pulley 67 upon the main-shaft 6. The bracket 53 carries a dependingfork 68 straddling a groove 69 provided between the gear 62 and a collar70 adjustably secured upon the gear hub, whereby said gear is caused topartake of'the lateral movements of the loop-taker and is constrained torotate with the actuating-shaft 64.

Fixed in a suitable aperture in the bracket 53, by a set-screw 71, isthe supporting-bar 72 of an upwardly extendingarm 7 3'having upon itsupper end a small, rectangular block 74, constituting a needle-throatand having a needle-aperture 75. The needle-throat block 74 projectsinto a suitable slot 76 formed in a throat-plate 77, secured upon thework-cylinder 2 and having a feed-dog slot 78. The throat-plate slot 76afi'ords suflicient clearance to provide for the lateral movements ofthe needle-throat block 74with the loop-taker.

The inner face 7 9 of the arm 73 is partly cut away to provide anoverhanging ledge 80 bedual purpose of guiding the needle and insuringthe formation of the needle-thread loops upon the looptaker side of theneedle. Projecting from the ledge are spaced lugs, as 82,. formingbetween them a stop-notch entered by the stop-lug 83 upon thelowerthread bobbin-case 59. Consequently, the bobbin-case rotationrestraining means occupies a predetermined relationship with respect tothe bobbin case regardless of the lateral movements of the loop-taker inwhich the bobbin-case is journaledLMeans, of a Well known character, areemployed, for providing a free thread-loop passage past the bobbin-caserotation restraining elements. This opener-mechanism includes theeccentric-actuated opener-finger 84 which intermittently engages an ear85 projecting from the bobbin-case.

The work-advancing mechanism comprises a feed-dog 86 verticallyadjustable upon a feed-bar 87 having a hub 88 embracing a mainfeed-eccentric 89 upon the loop-taker actuating shaft 64. Projectinglaterally from the feed-bar is a'pin 90 pivotally' embraced by anapertured end of a link 91, of which the opposite end is similarlyconnected with a crank-arm 92 upon a feed rockshaft 93. The rock-shaft93 is journaled in suitable bearings in the work-cylinder 2 and at itsrearward end carries a crank-arm 94 connected by a pitman 95 with anauxiliary feed-eccentric 96 upon the main-shaft 6. ,Theauxiliarycccentric 96, in the present in stance, is constructedsubstantially in accordance with the disclosure in the patent to W. F.Dial et al., No. 718,988, Jan. 27, 1903, and is therefore adjustable tochange the de ree of rocking movement imparted to the roc -shaft 93. Byadjusting the auxiliary-eccentric 96 into neutral position, the extentof feed motion is determined entirely by the action of the eccentric 89to rock the feed-bar 87 about its pivotal connection with the link 91.The efiective work-feeding action of the eccentric 89 may, therefore, beincreased or diminished by adjusting or retaining themixiliary-eccentric 96 to actuate the feed rockshaft 93 in properlytimed relation with respect to the main rotating eccentric 89, as willbe self evident.

The free end of the work-cylinder 2 is closed by a cylindrical end-cap97 slidingly fitted upon the cylinder for ready access to the operatingmechanism enclosed thereby. Opposed to the feed-dog 86 is a presser-foot98 which may be of any construction suitable to the work to be stitched.

It is believed that the operation of the machine is clearly understoodfrom the foregoing description of the mechanism thereof. The endwisereciprocatory needle 10 is later ally vibrate-fl in a directioncrosswise of the feed-direction and therefore efiects the production ofzigzag lock-stitches. The eccentrio-actuated two-armed pitman 16, 17,which imparts thelateral vibrations to the needle, likewise transmitsbodily lateral movements to the verticahaxis loop-taker in a directionlengthwise of the work-cylinder, thereby a maintaining a predeterminedloop-seizing relationship between the needle and looptaker, regardlessof the extent of lateral vibration of the needle.

-Having thus set forth the nature of the invention, what I claim. hereinis:

1. A sewing machine having a needle-bar, a vibratory-frame in whichsaidneedle-bar is j ournaled for endwise reciprocation, means forreciprocating said needle-bar, and means I for imparting vibratorymovements to said frame including a rotary actuating-eccentric, a pitmanhaving a strap embracing said eccentric to derive circular movementstherefrom, a reciprocating pivotal-support for said pitman, andoperative connections between the pitman and said frame.

2. A sewing machine having a needlebar, a vibratory-frame in which saidneedle-bar is journaled for endwise reciprocation, means forreciprocating said needle-bar, a rotary actuat1ng-eccentr1c, a two-armedpitman having a strap between its ends embracing saidactuating-eccentric, a reciprocatingfpivotalsupport for one of the armsofsaid pitman, and a link-connection between the other pitman-arm andsaid frame for imparting lateral movements to said needle-bar.

4. A sewing. machine having a needle-bar,

a vibratory-frame in which said needle-bar is a g journaled for-endwlsereciprocation, a rotary $1 1 needle-reciprocating shaft, a n'eedlebarvibrating shaft disposed transversely and rotating at one halff'thespeed of the needlereciprocating shaft, an eccentric adjustably carriedby said needle-vibrating shaft, a twoarmed pitman having a strapintermediate its ends embracing said eccentric,a reciprocatingpivotal-support for one arm of said'pitman, and an operative connectionbetween the other arm of the pitman and said frame to. j

5. A sewing machine having a needle-carrying bar, a loop-takercooperating with the needle carried by saidbar 1n the formation fortransmitting vibratory movements thereof stitches, a vibratory-frame inwhich the needle-bar is journaled for endwise reciprov cation, means forreciprocatingv said needlebar, a rotary actuating-eccentric, a pitmanhaving a strap embracing said eccentric, a

link connecting the pitman with said vibratory frame, and meansincluding a reciprocating pivotal-support for said pitman fortransmitting the endwise movements of the pitman to said loop-taker tocompensate for the lateral vibrations of the needle.

6. A sewing machine having a needle-can 'rying bar, a loop-takercooperating with the .said vibratory-frame for imparting lateralmovements to the needle, and operative connections between the other armof the'pitman and said loop-taker for imparting movements 'to theloop-taker compensating for the lateral movements of the needle.

7. A sewing machine having a needlecarrying bar, a loop-takercooperating with the needle carried by said bar in the formation ofstitches, a Vibratory-frame in which the needle-bar is jonrnaled forendwise reciprocation, means for reciprocating said needle-bar, a rotaryactuating eccentric, a twoarmed pitman having a strap intermediate itsends embracing said eccentric, a link connecting one arm of the pitmanwith said vibratory-frame, a rock-lever pivotally connected with theother arm of said pitman, and connections with said rock-lever fortransmitting bodily lateral movements to the looptaker to compensate forthe lateral vibrations of the needle.

8. In a sewing machine having a workcylinder and a bracket-armoverhanging the workcylinder, a needle-ca rrying bar, a vibratory-framemounted in tne bracke -arm in which the needle-bar is j'ournaled forendwise reciprocation, means for reciprocating the needle-bar, means forvibrating said frame, a vertical-axis rotary loop-taker cooperating withthe needle in the "formation of lockstitches, a bobbin-case ournaled insaid looptaker, a bracket movably supported by the work-cylinder inwhich said loop-taker is jonrnaled to seize needle-thread loops at theside of the needle opposite to the free end of the work-cylinder, aneedle-throat carried by said bracket for reciprocation therewith, meanscarried by said bracket for restraining the bobbin-case against rotationwith said loop-taker, and means for reciprocating said bracketlongitudinally of the work-cylinder in timed. relation with the lateralvibrations otthe needle to maintain loop-seizing relationship betweenthe needle and the looptaker.

9. In sewing machine having a work-cylinder and a bracket-armoverhanging the work-cylinder, a needle-carrying bar, a vibratory-framemounted in the bracket-arm for swinging movements in the direction ofthe length of the work cylinder, in which frame the needle-bar isjonrnaled for endwise recipe rocation, means for reciprocating theneedle bar, a rotary actuating eccentric jonrnaled in said bracket-arm,a two-armed pitman having a strap intermediate its ends embracing saideccentric, operative connections between one arm of the pitman andsaid'vibratory-frame, a rock-lever pivotally connected with the otherarm of said pitman, a second rock-lever, an extensible ball-jointconnection between said rock levers, a rotary loop-taker supported forreciprocation longitudinally of the cylinder, means for rotating saidloop-taker, and operative connections for reciprocating said loop-takerfrom said second rock-lever.

10. A sewing machine having needlecarrying bar, a vibratory-frame inwhich the needle-bar is jonrnaled for endwise reciprocation, means forreciprocating the needlebar, means for laterally Vibrating said frame, avertical-axis rotary loop-taker cooperating with the needle carried bysaid bar in the formation of lock-stitches, a bobbin-case journaled insaid loop-taker, a bracket in which said loop-taker is journaled, meansfor rotating the loop-taker, means for reciprocating said bracket intimed relation with the needlevibrations to maintain loop-seizingrelation between the needle and loop-taker, an arm having aneedle-throat carried by the bracket for reciprocation therewith, andcoaoting elements upon the needle-throat arm and the bobbin-case forrestraining said bobbin-case against rotation with the loop-taker.

In testimony whereof, I have signed my name to this specification.

WVALTER MYERS.

